This application is based on and incorporates herein by reference Japanese Patent Application No. 2000-124337 filed on Apr. 25, 2000.
1. Field of the Invention
The present invention relates to a motor holder for holding a motor.
2. Description of Related Art
A motor holder for holding a vehicular blower motor to be secured to a vehicle body has been generally manufactured from an iron plate material. However, recently, a resin material is predominantly used for manufacturing the motor holder for the purposes of weight reduction and standardization.
One example of such a motor holder will be described with reference to FIGS. 7 and 8. FIG. 7 is a front view of a previously proposed motor holder 21 and a blower motor 20 received in the motor holder 21. FIG. 8 is a bottom plan view of the motor holder 21 (seen in a direction of an arrow A in FIG. 7).
With reference to FIG. 7, a motor case 22 of the blower motor 20 is a generally cylindrical hollow body. An armature (not shown) is rotatably supported within the motor case 22 via a rotatable shaft 23. Magnets (not shown) for generating a rotational force of the armature are secured to an inner peripheral surface of the motor case 22.
The motor holder 21 is made of a resin material. Furthermore, as shown in FIGS. 7 and 8, the motor holder 21 includes a motor housing segment 25 for receiving the blower motor 20, a venturi ring segment 26 and a plurality of connecting members 27 that connect the motor housing segment 25 to the venturi ring segment 26. With reference to FIG. 8, the venturi ring segment 26 is constructed to circumferentially surround an outer peripheral surface of the motor housing segment 25. The connecting members 27 extend radially outwardly from the outer peripheral surface of the motor housing segment 25. Radially outer ends of the connecting members 27 are connected to the venturi ring segment 26.
In the motor holder 21, a thickness of each segment is minimized (1-3 mm thick) to achieve both the weight reduction of the motor holder 21 and the improved moldability of the resin material. Since the thin resin material that has a lower rigidity than the iron plate material is used in manufacturing of the motor holder 21, the motor holder 21 is prone to generate vibrational noise during operation of the blower motor 20. However, as described above, the radial connecting members 27 are formed to extend in the radial direction in the motor holder 21. Thus, the rigidity of the motor holder 21 is improved, so that the vibrational noise generated during the operation of the blower motor 20 is reduced.
However, as shown in FIG. 8, in the motor holder 21 having the radial connecting members 27, although the rigidity in an axial direction (direction of an arrow B in FIG. 7) is fairly sufficient, the rigidity in a circumferential direction (direction of an arrow C in FIG. 8) is insufficient, so that relatively large vibrational noise can still be generated. Thus, there is still a need to further reduce the vibrational noise.
The present invention addresses the above disadvantages. Thus, it is an objective of the present invention to provide a motor holder having a reduced vibrational noise level during operation of a motor that is received in the motor holder.
To achieve the objective of the present invention, there is provided a motor holder for holding a motor. The motor holder includes a motor housing segment, a plurality of radial connecting members and a venturi ring segment. The motor housing segment receives and supports the motor. The radial connecting members extend radially outwardly from an outer peripheral surface of the motor housing segment. The venturi ring segment is connected to radially outer ends of the radial connecting members and circumferentially surrounds the motor housing segment. The motor holder further includes a plurality of oblique connecting members. Each one of the oblique connecting members is arranged between and is connected to each adjacent two radial connecting members. Furthermore, each one of the oblique connecting members is oblique to a radial direction that extends from the motor housing segment.